1. Field of the Invention
The present invention relates to magnetic levitation, and more specifically, it relates to inductrack systems.
2. Description of Related Art
Inductrack is a completely passive, fail-safe magnetic levitation system, using only unpowered loops of wire in the track and permanent magnets (arranged into Halbach arrays) on the vehicle to achieve magnetic levitation. The track can be in one of two configurations, a “ladder track” and a “laminated track”. The ladder track is made of unpowered Litz wire cables, and the laminated track is made out of stacked copper or aluminum sheets.
There are two prior art designs: the Inductrack I, which is optimized for high speed operation, and the Inductrack II, which is more efficient at lower speeds.
Inductrack was invented by a team of scientists at Lawrence Livermore National Laboratory, headed by physicist Richard F. Post, for use in maglev trains. The only power required is to push the train forward against air and electromagnetic drag, with increasing levitation force generated as the velocity of the train increases over the loops of wire.
Its name comes from the word inductance or inductor; an electrical device made from loops of wire. As the magnet array (with alternating magnetic field orientations) passes over the loops of wire, it induces a current in them. The current creates its own magnetic field which repels the permanent magnets. The Inductrack II variation uses two Halbach arrays, one above and one below the track to double the levitating magnetic field without substantially increasing the weight or footprint area of the Halbach arrays, while having lower drag forces at low speeds.